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-   -   Reserved for MF - Sequence 3408 (https://www.mersenneforum.org/showthread.php?t=18421)

fivemack 2015-06-05 09:06

msieve -v -nc1 filter_maxrels=200000000

If you're doing experiments on this relation set, I would be interested also to see what the minimum relation count is for target_density=120 to work; my suspicion is that, with 32-bit large primes, it's worth doing enough oversieving to get a higher target density even if you're not doing the sieving and linear algebra on the same hardware.

At least at one point you had to put
[code]
msieve -v -nc1 "filter_maxrels=200000000 target_density=120"
[/code]
(note the quotes) to get the arguments parsed correctly; not sure if this has now been fixed.

VBCurtis 2015-06-08 16:01

3408:1589 is factored, p65*p97. 1590 was easy. 1591 has a C157 which has survived a t40 and 600 curves @ 11M; I am running a standard t45 on it now, and welcome assistance for whatever part of a t50 is proper.

I used -s flag to update factordb for the sequence; it appears that since aliqueit is managing the ECM presently, the p25 already found in 1591 wasn't uploaded. Sorry 'bout that!

I'll tinker with the filtering step and report my findings- there aren't many 32-bit runs on C162s out yet.

VBCurtis 2015-06-10 23:20

A t45 is complete on the C157 at i1591. I have completed 400 curves at B1 =43M, and will finish 1000 more.

I will NFS this C157 in July if nobody claims it before then.

Findings on the C162 with 32LP:
233M relations could not build a matrix.
236M relations produced a matrix size 9.53M.
240M relations with default target-density, the actual run, was a matrix of size 8.78M. This took 320 thread-hours to solve. The last 4.4M relations took 48 thread-hours to sieve on the same machine.
Target-density 80 produced 8.25M matrix.
Density 90 produced 7.83M matrix.
Density 96 produced 7.62M matrix.
Density 100 could not build a matrix.
Making a broad assumption that matrix solve time scales with the square of the size of the matrix, a 9.53M matrix would have taken 45-50 extra thread-hours to solve, so my "oversieving" cost me no net time even at default density. If I'd set target-density to 90 or 96, I could have saved ~25% of the matrix step, or 70-80 thread-hours (plus the ~50 saved already from 236M rels vs 240M rels at default density!). 50 hours extra sieve, 100+ hours saved in matrix step.

My data matches fivemack's opinion, that for 32LP the extra sieve time is more than made up in shorter matrix steps; I will set target-density to 96 or higher for my next 32-bit project.

I once edited the factmsieve script to add target-density in, but have lost those changes. Can someone remind me where to place the flag? I suppose it'll take just a couple attempts to get the edit syntax correct anyway..

Batalov 2015-06-11 01:59

[QUOTE=VBCurtis;403847]I once edited the factmsieve script to add target-density in, but have lost those changes. Can someone remind me where to place the flag? I suppose it'll take just a couple attempts to get the edit syntax correct anyway..[/QUOTE]
You put it in quotes behind the -nc1, like
msieve {...other params...} -nc1 "target_density=96"
When in doubt, run
msieve -h

VBCurtis 2015-06-11 06:13

My doubt was about the python script, rather than the msieve invocation. Makes sense it is as simple as searching for "-nc1" in the script and adding the flag as if it were command line.

Thanks!

VBCurtis 2015-06-14 03:19

A total of 1550 curves at B1 = 43M are complete on the current c157.
If nobody takes this number on, I will find resources in July to perform NFS.

swellman 2015-10-20 23:35

Did the C157 ever get the full t50? I can't take on the NFS job right now but I can help with ECM (if needed).

VBCurtis 2015-10-21 02:27

I never did the NFS, as my cuda-enabled msieve rig failed in June so I lost my poly-searching setup. I'll be happy to do the NFS if the usual suspects can procure a suitable poly. Perhaps 500-1000 more curves first?

swellman 2015-10-21 09:29

Ok I will run some additional ECM pending a poly being found. I don't have a GPU rig to aid with the poly select either or I'd help with that.

Should this thread become sticky once again?

RichD 2015-10-24 03:34

C157 @ i1591
 
I ran A5 to 5M and the two best are:
[CODE]N: 9622573172947172690216533113544901989270930284548712969416487159589518659037713792560995347053599943835805911303098595474551471251812082141957434773586035021
# expecting poly E from 1.91e-12 to > 2.20e-12
R0: -1226437530675169727727847599102
R1: 4489146410702701
A0: 1085620711869412190796638577436472845
A1: -13524714026065933306465543047704
A2: 2354089978283392085793977
A3: 22197682057227374702
A4: 2053627590300
A5: 3467880
# skew 1073123.83, size 2.686e-15, alpha -7.096, combined = 2.044e-12 rroots = 3[/CODE]

[CODE]N: 9622573172947172690216533113544901989270930284548712969416487159589518659037713792560995347053599943835805911303098595474551471251812082141957434773586035021
# expecting poly E from 1.91e-12 to > 2.20e-12
R0: -3726397299028232594516190800757
R1: 228399129977819
A0: -275716441178826782149000795012629753184
A1: 374337043347538241259074213027768
A2: 35851573769457152514399928
A3: -3163034830851676700
A4: -195302199429
A5: 13392
# skew 12398157.51, size 2.645e-15, alpha -6.725, combined = 2.039e-12 rroots = 1[/CODE]

VBCurtis 2015-10-24 05:46

I'll test-sieve these two and pick one to run, then I'l wait for Swellman's last ECM run before commencing NFS.


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